The present disclosure relates to a coordinate measuring machine and, more particularly, to a non-articulated portable coordinate measuring machine.
Portable articulated arm coordinate measuring machines (AACMMs) have found widespread use in the manufacturing or production of parts where there is a need to rapidly and accurately verify the dimensions of the part during various stages of the manufacturing (e.g. machining) or production of the part. Portable AACMMs represent a vast improvement over known stationary or fixed, cost-intensive, and relatively difficult to use measurement installations, particularly in the amount of time it takes to perform dimensional measurements of relatively complex parts. Typically a user of a portable AACMM simply guides a probe along the surface of the part or object to be measured. The measurement data are then recorded and provided to the user. In some cases, the data are provided to the user in visual form, for example, three dimensional (3-D) form on a computer screen. Alternatively, the data may be provided to the user in numeric form, for example, when measuring the diameter of a hole, the text “Diameter=” is displayed on a computer screen.
Conventional AACMMs include a plurality of axially rotating joints connected by rigid arm segments. The overall range of motion of the AACMM is determined by the number of rotating joints as well as the length of each rigid arm segment. Common configurations of a portable AACMM system include three or four rigid arm segments pivotable about six or seven axes of rotation. Because each arm segment is rigid, and each rotating joint is rotatable about only one axis, movement of a portable AACMM is inherently limited. For example, a portable AACMM cannot bend to measure between two curved concentric surfaces positioned relatively close to one another.